Allow static background in metadata to be a Dask array

[hakonanes]

Signed-off-by: Håkon Wiik Ånes hwaanes@gmail.com

Description of the change

• Fix Allow the static background in EBSD metadata to be a dask array in EBSD.remove_static_background() #399.

After v0.5 has been released, bug fixes such as this should be branched off of main and merged back into main, possibly with the necessary patch release updates (changelog, patch version increment) included so we could release a patch release immediately.

Progress of the PR

• Docstrings for all functions
• Unit tests with pytest for all lines
• Clean code style by running black via pre-commit

Minimal example of the bug fix or new feature

The following doesn't throw a TypeError

>>> import kikuchipy as kp
>>> import dask.array as da
>>> s = kp.data.nickel_ebsd_small()
>>> s.metadata.Acquisition_instrument.SEM.Detector.EBSD.static_background = da.from_array(s.metadata.Acquisition_instrument.SEM.Detector.EBSD.static_background)
>>> s.remove_static_background()

For reviewers

• The PR title is short, concise, and will make sense 1 year later.
• New functions are imported in corresponding __init__.py.
• New features, API changes, and deprecations are mentioned in the unreleased
  section in doc/changelog.rst.
• New contributors are added to .all-contributorsrc and the table is regenerated.